M321RBJA0M22-CLPYL Samsung DDR5 6400MBPS Pc5-51200 RAM

Samsung DDR5 Server Memory Module

This high-performance computing component is engineered for enterprise-grade reliability and exceptional data throughput in demanding server environments.

Comprehensive Product Specifications

Manufacturing and Identification

• Brand: Samsung
• Manufacturer Part Code: M321RBJA0M22-CLPYL
• Product Designation: 256GB DDR5 Synchronous Dynamic Random-Access Memory Component

Performance and Architecture

Capacity and Configuration

• Total Storage: 256 Gigabytes (configured as a single module)
• Memory Generation: Cutting-edge DDR5 SDRAM technology

Speed and Data Transfer

• Data Rate: 6400 Megabits per second
• Classification: PC5-51200 (DDR5-6400)
• Timing Parameter: CAS Latency 40 (CL40)
• Operating Voltage: 1.1 Volts

Advanced Server Features

• Error Management: Integrated Error Correcting Code (ECC)
• Signal Stabilization: Registered (Buffered) design for enhanced signal integrity
• Internal Organization: 4Rank by 4 (4Rx4) architecture

Physical Construction and Dimensions

• Connector Type: 288-pin Registered Dual In-Line Memory Module (RDIMM)
• Module Profile Height: 1.00 inch
• Module Depth Length: 6.75 inches

Samsung M321RBJA0M22-CLPYL 256GB DDR5 Memory Module

Samsung's M321RBJA0M22-CLPYL 256GB DDR5 6400MT/s PC5-51200 Registered ECC RDIMM represents a new class of high-capacity server memory engineered for data centers, enterprise servers, and high-performance computing platforms. Built to industry specifications with ECC (Error Correcting Code), Registered buffering, and a 288-pin RDIMM form factor, this module balances extreme capacity with reliability and predictable performance under demanding workloads. With a low operating voltage of 1.1V and a CAS latency (CL) of 40, the part is optimized for dense memory configurations and modern CPU architectures that benefit from high-bandwidth DIMMs.

Technical Specification and Memory Architecture

At its core, the M321RBJA0M22-CLPYL is a DDR5 memory module capable of operating at DDR5-6400 speeds (commonly referred to as 6400MB/s or 6400MT/s), aligning with the PC5-51200 performance class. The module's 256GB capacity is achieved through Samsung's advanced die stacking and high-density memory IC technology. The ECC Registered architecture integrates on-module register and ECC logic that reduce electrical loading on the memory controller while maintaining data integrity by automatically detecting and correcting single-bit errors. The 288-pin RDIMM layout is compatible with server motherboards that support registered DDR5 memory, and the module's 1.1V nominal voltage reflects DDR5's energy-efficient advancements compared to earlier generations.

Latency, Frequency, and Power Characteristics

Latency and frequency are critical to understanding real-world performance. The CL40 timing indicates a CAS latency of 40 cycles at the rated 6400MT/s speed; while raw cycle counts may appear higher than some lower-frequency DIMMs, the increased transfer rate compensates and delivers greater effective bandwidth. Operating at 1.1V, the module strikes a favorable balance between performance and power consumption—particularly important in large-scale deployments where overall memory power draw can materially affect thermal design and operating cost. Samsung's internal production and validation ensure these timing and power characteristics are held within server-grade tolerances.

Compatibility and Platform Considerations

Compatibility is a key consideration for procurement teams and system builders. The module is intended for server-class motherboards and platforms explicitly supporting DDR5 Registered ECC RDIMMs and PC5-51200 speeds. Compatibility can vary by server vendor and BIOS/firmware revisions; therefore, it is essential to consult motherboard and server vendor memory support lists before purchase. Many OEM platforms require specific SPD (Serial Presence Detect) configuration or may limit maximum supported speed depending on population and CPU memory controller capabilities. Samsung's module adheres to JEDEC standards for DDR5 Registered DIMMs, increasing cross-vendor interoperability when used in supported systems.

Performance In Data-Intensive Workloads

High bandwidth memory like the M321RBJA0M22-CLPYL is designed to accelerate memory-bound workloads. Workloads such as in-memory databases, large-scale virtualization, analytics processing, AI training and inference, and high-frequency transaction processing benefit directly from increased transfer rates and large per-module capacity. The 256GB density allows system architects to reduce the number of sockets or DIMM slots occupied to reach desired memory footprints, simplifying memory channel balancing and often improving effective memory throughput in multi-socket servers. Where memory capacity has historically been a constraint, modules of this size make it practical to consolidate more data into RAM for faster access.

Scalability and Memory Topologies

Scalability is a driver for choosing high-density modules. When designing systems that require terabytes of memory, administrators often choose fewer high-density RDIMMs over many lower-capacity modules to reduce complexity and improve signal integrity. Using the M321RBJA0M22-CLPYL in multi-channel and multi-socket topologies requires attention to channel population rules and balancing to preserve optimal performance. Properly distributed modules across channels and sockets reduce contention and make the most of a system's memory bandwidth. Samsung's RDIMMs are often incorporated into carefully engineered configurations that maximize theoretical throughput while staying within power and thermal limits.

Thermal and Mechanical Considerations

Physically, the 288-pin RDIMM conforms to standard server DIMM dimensions but may include heat spreaders or label materials that impact airflow. When deploying in dense rack servers with multiple populated DIMM slots, ensure that chassis airflow and cooling capacity are adequate to dissipate the cumulative heat generated by CPU, storage, and memory. While DDR5's efficiency reduces per-module power in many scenarios, high-density and high-frequency modules still contribute to thermal load. System integrators should verify that airflow paths are unobstructed and that no additional mechanical constraints—such as oversized CPU coolers or cable routing—interfere with DIMM installation or cooling performance.

Security, Data Integrity, and Compliance

Data integrity and security are paramount in regulated industries and large-scale deployments. ECC functionality plays an essential role in maintaining integrity, but system-level practices such as secure boot, firmware signing, and memory encryption (available on some platforms) complement hardware ECC by protecting against more complex threats. Enterprises that must meet regulatory frameworks should document memory configuration, validation steps, and firmware levels as part of their compliance evidence. Samsung's enterprise memory modules are designed to integrate into secure infrastructure stacks and support the traceability and quality documentation required by many auditing processes.

Comparison With Other Memory Types and Generations

Comparing DDR5 RDIMM to DDR4 and other memory types clarifies value propositions. DDR5 increases per-channel bandwidth and introduces features such as Decision Feedback Equalization (DFE) and improved power distribution (VDD/VDDQ changes), enabling higher frequency operation and greater capacity per module. Compared to unbuffered UDIMM memory intended for desktops, RDIMMs trade slightly higher latency for the benefits of signal integrity, higher stability in multi-DIMM configurations, and superior suitability for server environments. Samsung's DDR5 RDIMM modules leverage these advances to deliver higher sustained throughput and better scalability for enterprise-class applications.

Environmental Considerations and Energy Efficiency

Energy efficiency matters for modern data centers aiming to reduce PUE (Power Usage Effectiveness) and operational expenses. The 1.1V operating voltage of this DDR5 RDIMM signifies an improvement in energy per bit transferred when compared to earlier generations. Deploying high-density modules also has a secondary environmental benefit: fewer physical DIMMs and potentially fewer servers to achieve the same memory capacity reduces material usage and chassis-level energy overhead. Coupled with efficient cooling and server consolidation strategies, adopting modern RDIMMs can contribute to a greener IT footprint while delivering superior application performance.

Real-World Benchmarking and Performance Metrics

Benchmarks for server memory should emphasize realistic, workload-aligned metrics rather than synthetic peak numbers alone. Memory-bound application benchmarks, such as large in-memory database throughput, multi-threaded analytics, and virtualization density tests, demonstrate the benefits of higher DIMM bandwidth and capacity. When testing the M321RBJA0M22-CLPYL in a controlled lab, measure latency-sensitive and bandwidth-sensitive scenarios, quantify ECC event rates, and profile thermal behavior under continuous load. Such empirical data helps IT teams predict production performance and determine whether the module’s capacity and frequency align with application service-level objectives.

Best Practices for Deployment At Scale

Deploying many high-capacity RDIMMs at scale requires disciplined practices. Maintain an inventory of validated firmware and BIOS revisions, follow OEM population maps to optimize channel balance, and document every configuration change to simplify troubleshooting. Consider rolling firmware updates and staged deployments to detect integration issues early, and use monitoring tools to track ECC error counts and DIMM temperature trends over time. Standardizing on a single module type across a fleet simplifies spare parts management and reduces complexity when provisioning new systems or performing field replacements.